As electronic systems continue to increase in density and operating speeds, severe electrical and mechanical demands are placed on the electrical connectors employed in the systems. The connectors must complete numerous high density electrical connections, yet they must be rugged and versatile and must comply with high-speed signal specifications.
FIGS. 1 and 3 illustrate an existing solution for the right angle interconnection of a mother-board and daughter-board where FIG. 3 is an enlarged partial, exploded perspective view of the assembly of FIG. 2. FIG. 1 is a perspective drawing and FIG. 2 an exploded drawing of an AMP-ASC.RTM. interconnection system which is commercially available from AMP Incorporated of Harrisburg, Pennsylvania. The AMP-ASC Interconnection System uses an innovative contact technology and support structure to provide a board-to-board connector that is higher density and can carry faster signals than conventional connectors. The illustrated connector is an AMP-ASC mother-board to daughter-board card-edge connector, and it is obviously made with a very small number of parts. As seen in the enlarged view of FIG. 3, canted coil springs 10 are seated in rigid metal core members 12, and core members 12 are then wrapped by a flexible etched circuit 14 to hold the canted coil springs 10 in place. Two such modules 2 are held side-by-side by plastic end caps 16. The completed assembly is mounted on a mother-board 5. The canted coil springs 10 provide high compliancy and nearly constant normal force through a wide range of deflection. Tightening the modules 2 against the mother-board 5 completes the appropriate electrical connections with the flexible etched circuit 14. Photolithographic fabrication of the flexible etched circuit allows routing of the appropriate conductive traces between the mother-board 5 and daughter-board 7. Hence, insertion of a daughter-board 7 between the two modules 2 compresses the canted coil springs 10 and completes the interconnection between the daughter-board 7 and the mother-board 5 via the flexible etched circuit. This and other AMP-ASC interconnection systems 10 can provide high fidelity interconnection of signals with rise-times of less than 0.3 nanoseconds and at densities up to 160 signal lines per inch.
However, there is ample room for improvement. The assembly and disassembly time of the above-described components (for servicing) is still excessive. More importantly, the manufacturing costs of the canted coil springs 10 are high.
For these reasons, there have been efforts at refining the canted coil springs 10. AMP Incorporated provides an alternative in the form of its AMPLIFLEX.RTM. compressible contacts. These AMPLIFLEX.RTM. compressible contacts include a flexible etched circuit having plurality of closely-spaced traces photographically etched or otherwise formed on a flexible film. The flexible etched circuit is wrapped around an elongate elastomeric core and is bonded thereto. The elastomeric core eliminates the need for the canted coil springs 10 and intricate molded core members 12 of FIG. 2. Consequently, AMPLIFLEX.RTM. compressible contacts are far less expensive to manufacture.
For this reason, it would be greatly advantageous to incorporate AMPLIFLEX.RTM. compressible contact technology in a right-angle zero insertion force connector of the type described in FIGS. 1 and 2.